Static random-access memory (SRAM) is a type of semiconductor memory that uses bi-stable latching circuitry to store each bit. The term static differentiates it from dynamic RAM (DRAM), which must be periodically refreshed to overcome leakage of charge within the DRAM. Typical SRAM is considered volatile because stored data is eventually lost when the memory is not powered.
An SRAM cell has three different states: standby (the circuit is idle), reading (the data has been requested), and writing (updating the contents). For the SRAM to operate in read mode and write mode, it should have “readability” and “write stability,” respectively.
A static RAM (SRAM) has a low memory capacity in comparison to a dynamic DRAM, but has an advantage that the SRAM has a higher operating speed. Accordingly, the SRAM has been widely used in a cache memory of a computer or a portable electronic device, which requires high speed operation.